Abstract

We have studied the reversal of the bulk and interfacial magnetizations of the free layer of a spin valve using soft x-rayresonant magnetic scattering. By dusting the interface of the NiFe free layer with a few angströms of Co, we were able to distinguish between the interfacial and bulk magnetisms by tuning the x-ray photon energy. We measured hysteresis loops of reflected x-ray intensity at selected points in reciprocal space. We find no difference in the switching fields, showing that in transition metal ferromagnets, the exchange interactions are sufficiently strong to prevent a separate interfacial coercivity from arising.

Received 31 March 2007Accepted 07 September 2007Published online 28 September 2007

Acknowledgments:

This work was supported by the EU Marie Curie fellowships through the Ultrasmooth Contract No. MRTN-CT-3003-504462, by the STFC through the CMPC, and by the EPSRC. We would also like to thank Brookhaven National Laboratory for the provision of NSLS beamtime.